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The sequence S is defined by Sn = 2(Sn – 1) – 4 for each int
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25 Jul 2018, 17:22
25 Jul 2018, 17:22
Expert Reply
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Question Stats:
92% (01:03) correct
7% (01:57) wrong based on 54 sessions
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The sequence S is defined by \(S_n = 2(S_{n – 1}) – 4\) for each integer n ≥ 2. If \(S_1 = 6\), what is the value of \(S_5\)?
(A) –20
(B) 16
(C) 20
(D) 24
(E) 36
(A) –20
(B) 16
(C) 20
(D) 24
(E) 36
Re: The sequence S is defined by Sn = 2(Sn – 1) – 4 for each int
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11 Aug 2018, 16:51
11 Aug 2018, 16:51
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Expert Reply
Explanation
The sequence \(S_n = 2(S_{n - 1}) - 4\) can be read as “to get any term in sequence S, double the previous term and subtract 4.”
The problem gives \(S_1\) (the first term) and asks for \(S_5\) (the fifth term):
To get any term, double the previous term and subtract 4. To get \(S_2\), double \(S_1\) (which is 6) and subtract 4: \(S_2 = 2(6) - 4 = 8\).
Continue doubling each term and subtracting 4 to get the subsequent term:
The sequence \(S_n = 2(S_{n - 1}) - 4\) can be read as “to get any term in sequence S, double the previous term and subtract 4.”
The problem gives \(S_1\) (the first term) and asks for \(S_5\) (the fifth term):
| 6 | ||||
| \(S_1\) | \(S_2\) | \(S_3\) | \(S_4\) | \(S_5\) |
To get any term, double the previous term and subtract 4. To get \(S_2\), double \(S_1\) (which is 6) and subtract 4: \(S_2 = 2(6) - 4 = 8\).
Continue doubling each term and subtracting 4 to get the subsequent term:
| 6 | 8 | 12 | 20 | 36 |
| \(S_1\) | \(S_2\) | \(S_3\) | \(S_4\) | \(S_5\) |
Re: The sequence S is defined by Sn = 2(Sn 1) 4 for each int
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05 Jul 2023, 06:50
05 Jul 2023, 06:50
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Thanks to another GRE Prep Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).
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